openpyxl.compat.singleton module

class openpyxl.compat.singleton.Cached(*args, **kw)

基类：type

Caching metaclass Child classes will only create new instances of themselves if one doesn’t already exist. Does not work with __slots__

class openpyxl.compat.singleton.Singleton(*args, **kw)

基类：type

Singleton metaclass Based on Python Cookbook 3rd Edition Recipe 9.13 Only one instance of a class can exist. Does not work with __slots__